When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I took my '07 C2S to the track last weekend with newly mounted PS2 N2 rubber after the PS4S ruined my last DE event because of the "mooshiness". You are right-it made the car scary to drive in high speed (120 MPH +) straights and turns. I had no idea what pressures to use so I did what you are suggesting-I measured before and after session pressures with a good gage. After adding 4 psi, taking out 2 psi, etc. I found that hot pressures of 43F/49R (37F/42R cold) worked the best. This surprises me because most people here are talking about much lower pressures than this. I did wear out the shoulders on the outer edges of the driver side tires but I think this was due to my sloppy driving technique.
I suggest you ask experienced 997 track drivers if those 43/49 track pressures are correct. I suspect your suspension (or alignment) needs work...
PS4S
I had them on my 993 C2S, drove for about 300-400km. Easily noticed that they felt a bit soft on the road, hard to describe well. This translated to less road feel and not as crisp handling. Short of it - didn't like them compared to the Pirelli's that were on there before. I was able to swap out for PS2 N spec and so far these are fantastic, car tracks and handles better and I can feel the road. You do feel more of the road like expansion joints and bumps. It's what I want out of the car. Comfort and longevity are not goals for the tires on this car.
PS2
997.2 C4S. I took off 2013 Super Sports and replaced with PS2 N spec. I decided to skip PS4s based on my 993 experience. I drove just over 1000km with the PS2, about 450 or so in the rain. No issues in rain of varying degrees from heavy to light (most of which were highway kms). In dry, I didn't have a chance to push the tires as the road didn't offer opportunities to put the tires to work. I think the tires have good road feel, handling is sharp. I think the tires does what I expect from it and will do so when pushed. Will drive more in the dry soon. Like the 993, goals are not tire comfort and longevity.
Both cars are lowered, one with Bilstein PSS10 (and wheel spacers) and the other with KW v3. 993 has RS alignment. Both have upgraded engine mounts. Neither will likely see track for track use, so not worried about tire performance there.
A discussion that will probably never end (:
I feel the need to jump in and give my 2 cents after a long and enjoyable time with my GTS.
So, The tire pressure I drove the first year with my GTS is not the tire pressure I drive today and the difference is huge. I have 235/35/19 / 305/30/19 and currently driving with pressures 29/30 psi front 33/34 psi rear (Cold). With these pressures the grip and communication is very good (I have PS4s).
I also highly recommend giving negative camber in the front. (-1.15/1.5) and negative camber in the rear (-1.5 at least).
Also, I will mention that I found another label of GT3 997.2 year 2011 (which does not exist in the thread) where the listed pressures are not 29/33 but 29/31. Only 2 psi difference between front and rear.
Thoughts..
Anyone requiring more performance from a tire, OEM brakes or suspension mods (save the DSC box for PASM equipped)....needs to get on a track!
So much untapped performance in OEM S, GTS and all GT models! Take HPDE classes if lap times are your thang.
Nio sure I would track an expensive Mich or Pirelli tire if driving at > 7/10 of car or your own performance potential.
Track tear and wear consumes tires and brakes like burning $20 bills, maybe 100s.
My year round higher temp drives always begin at 30/37 psi cold.
When my (very accurate) TPMS show 37/44, I back off rather than deflate.
Re-inflating is a pain when driving in LA, especially at night.
Bought a mini tire pump, but it blows the 15A fuse in center console and the passenger footwell one is rated at 10A.
Might be missing out on untapped grip that low inflation might unlock- but my tire wear is dead even, ride is great and any additional tire noise is drowned out by my PSE with Sharky center muffler delete X-pipe!
Not screwing around with OEM alignment settings, everything works in harmony at the level I flog the crap out mine...while observing all speed zones posted signs. /s
YMMV
Last edited by Liste-Renn; 11-09-2023 at 01:40 AM.
My experience with PS4S is on a couple different cars, the most recent being my 911. I have noticed the biggest difference in feel is noticed when cornering aggressively. Compared to the previous tire it feels squishy in the corners. After some "break-in" miles on the PS4S I've gotten more comfortable with the different feel and it doesn't seem as bad. The cornering grip is fantastic, you just have to build your confidence with trusting the tire to do it's job.
Curious what the previous tire is you are comparing with.
I replaced Mich PSS with MPS4S, but also went from 8.5 & 11 X 19 to 9 &12 X19 wheels and 235/35 305/30 to 245/35 325/30 rubber.
Also installed a DSC PASM box, so changed several handling determinants at once.
First, startling performance increase from turn in precision to apex grip. Also allowed earlier turn exit full throttle- which, to me, is the single most fun trait of our RWD, engine behind rear axle. The MPS4S has far more acceleration grip than the already excellent PPSS. At least on my car.
Slow in, fast out. If you cannot apply full throttle on corner exit, you entered it too hot.
If you are braking mid corner, way too fast an entry.
I trail brake on occasion to assist turn in with more weight transfer, maybe more than with the MPSS.
So that might be a nod to the SS as far as turn in "feel"- which, as you posted, affects confidence.
The 4S is dead on accurate, and ultimately became more comfortably trusting it- especially after wearing off the casing compound and figuring out the best cold PSI to give me perfect PSI at operating temp.
Love the discussion, since most of us only get to drive on one set of wheels on the same car- back to back comps are impossible, for me.
Changing other parts, even motor/tranny mounts, are other variables that figure into the equation.
Trying to learn here and RL sure has a bevy of knowledgeable owners who are not afraid of modding for street driving performance gains.
Last edited by Liste-Renn; 11-09-2023 at 11:05 AM.
Curious what the previous tire is you are comparing with.
I replaced Mich PSS with MPS4S, but also went from 8.5 & 11 X 19 to 9 &12 X19 wheels and 235/35 305/30 to 245/35 325/30 rubber.
Also installed a DSC PASM box, so changed several handling determinants at once.
First, startling performance increase from turn in precision to apex grip. Also allowed earlier turn exit full throttle- which, to me, is the single most fun trait of our RWD, engine behind rear axle. The MPS4S has far more acceleration grip than the already excellent PPSS. At least on my car.
Slow in, fast out. If you cannot apply full throttle on corner exit, you entered it too hot.
If you are braking mid corner, way too fast an entry.
I trail brake on occasion to assist turn in with more weight transfer, maybe more than with the MPSS.
So that might be a nod to the SS as far as turn in "feel"- whic as you posted, affects confidence.
The 4S is dead on accurate, and ultimately became more comfortably trusting it- especially after wearing off the casing compound and figuring out the best cold PSI to give me perfect PSI at operating temp.
Love the discussion, since most of us only get to drive on one set of wheels on the same car- back to back comps are impossible, for me.
Changing other parts, even motor/tranny mounts, are other variables that figure into the equation.
Trying to learn here and RL sure has a bevy of knowledgeable owners who are not afraid of modding for street driving performance gains.
I so agree with what you wrote. Porsche loves the throttle (keeping the throttle in the turn and the throttle at the exit of the turn = grip and fun). My next set of tires will probably be CUP2 or PS4s again.. Hopefully by then I'll have B16 too😜
I must admit I was alone in not liking the PS4S on an M5 in 2018, Ive never been brave enough to try them again and very happy with Continental contact 7's on the 997.2 C2
Curious what the previous tire is you are comparing with.
I replaced Mich PSS with MPS4S, but also went from 8.5 & 11 X 19 to 9 &12 X19 wheels and 235/35 305/30 to 245/35 325/30 rubber.
Also installed a DSC PASM box, so changed several handling determinants at once.
First, startling performance increase from turn in precision to apex grip. Also allowed earlier turn exit full throttle- which, to me, is the single most fun trait of our RWD, engine behind rear axle. The MPS4S has far more acceleration grip than the already excellent PPSS. At least on my car.
Slow in, fast out. If you cannot apply full throttle on corner exit, you entered it too hot.
If you are braking mid corner, way too fast an entry.
I trail brake on occasion to assist turn in with more weight transfer, maybe more than with the MPSS.
So that might be a nod to the SS as far as turn in "feel"- whic as you posted, affects confidence.
The 4S is dead on accurate, and ultimately became more comfortably trusting it- especially after wearing off the casing compound and figuring out the best cold PSI to give me perfect PSI at operating temp.
Love the discussion, since most of us only get to drive on one set of wheels on the same car- back to back comps are impossible, for me.
Changing other parts, even motor/tranny mounts, are other variables that figure into the equation.
Trying to learn here and RL sure has a bevy of knowledgeable owners who are not afraid of modding for street driving performance gains.
Assuming you were asking me, I came from Pole Position S04’s on my 911. It’s a hard/stiff tire that evokes confidence in corners but I noticed it reached its edge sooner than the PS4S does. Also did not like how they often “flat spotted” after sitting for half a day and you could feel it for the first couple minutes of driving.
I also had Pole Position S04’s on my ‘15 S4 several years ago that had same “flat spotting” issue. Tire felt good otherwise but on track it lost grip before the PS4S did that I replaced it with. On my S4, when it was time to replace the PS4S I tried a different tire that came highly recommended from a friend with the same car. Firestone Indy 500. Great price point and the dry weather performance felt great compared to the PS4S. The Indy 500 suffers a lot compared to the PS4S in terms of wet weather handling, but I do prefer it in the dry. If the sizes were available for the 911 I’d run an Indy 500 for sure.
At the end of the day, there’s a reason the MPS4S is the gold standard that everyone compares to. It’s a phenomenal tire that has the ability to do everything very well. Maybe not the best at any one thing in particular but great at all things. Jack of all trades, master of none…
Tires, I suspect, are a lot like comparing high-end speakers.
Any audiophile pair you take home will be very good- and without sitting in a demo room with a direct A/B comparison switch- a definitive analysis is difficult,
At my limited driving skill level, and despite the fact I drive mostly now in SoCal without wild temp extremes...I do encounter rain (even in Vegas) and low temps (even snow) cresting an 8000' pass on the ACH. Having a tire that, as posted above, does several things well (but not willing to make the untenable choice of an "All Season" tire)is my best choice.
I really like the PS4S. At first, I did notice that it didn’t seem as sharp in the corners as the N rated Bridgestones I had on before, but the ride is so much better and they still have great grip. I’d buy em again.
Took me a minute to get mine right (as mentioned in this thread 2 years ago) but 2 years later I am very happy with them and would also buy them again without a second thought. Just don't run them at high pressures, I target 33/39 hot for canyon drives and they are great at those temps.
A discussion that will probably never end (:
I feel the need to jump in and give my 2 cents after a long and enjoyable time with my GTS.
So, The tire pressure I drove the first year with my GTS is not the tire pressure I drive today and the difference is huge. I have 235/35/19 / 305/30/19 and currently driving with pressures 29/30 psi front 33/34 psi rear (Cold). With these pressures the grip and communication is very good (I have PS4s).
I also highly recommend giving negative camber in the front. (-1.15/1.5) and negative camber in the rear (-1.5 at least).
Also, I will mention that I found another label of GT3 997.2 year 2011 (which does not exist in the thread) where the listed pressures are not 29/33 but 29/31. Only 2 psi difference between front and rear.
Thoughts..
You are in the ballpark. Since the 996 PAG has been lowering recommended tire pressures and significantly lowered them with the 991. For low load (driver and one passenger, no luggage) I use 31/34PSI cold on PS4S. And of course, as PAG states below 160MPH . It works.
09-27-2021, 04:43 PM
. It works. 